Previews from the Intl. Journal of Applied Ceramic Technology—April 2012

New papers that have been accepted for publication in the International Journal of Applied Ceramic Technology are posted to “Early View” on the Wiley website and can be read even before the issue is printed. Below are summaries of selected papers currently available via Early View.

All members of The American Ceramic Society receive free online access to the journal. To access any of the ACerS journals, or to become a member, visit www.ceramics.org.

These researchers from the Chinese Academy of Sciences impregnated porous, green reaction-bonded silicon carbide preforms with phenol-formaldehyde resin prior to silicon infiltration. They report that the phenol-formaldehyde impregnation decreased the porosity, increased the carbon content and improved the strength of the green preforms, which resulted in a significant increase in flexural strength and decreased residual silicon content of the RBSC.

Aguilar-Elguézabal and Bocanegra-Bernal, from Mexico’s Laboratorio Nacional de Nanotecnología, added 2.5-weight-percent Al2O3 whiskers to and then conventionally sintered an Al2O3(n) + 70-weight-percent ZrO2 nanocomposite. They report that the fracture toughness of the whisker-reinforced Al2O3-toughened ZrO2 was 62 percent higher than Al2O3, which makes it a promising biomedical material for medical and dental applications.

This team of researchers from China’s Shenyang University and Northeastern University studied the effect on repulsive force of adjusting the pH and adding poly(acrylic acid) dispersant on SiC, Al2O3 and ZrO2(3Y) single-component powders and on SiC-Al2O3-ZrO2(3Y) mixed powders. The team reports that the surface modification caused the mixed powders to be well dispersed because of the electrostatic repulsive force and steric hindrance offered by the PAA.

This team of researchers from India’s University of Lucknow and Mahanand Mission Harijan College prepared 0- to 4-weight-percent silver-loaded WO3 pellets. The team reports that the resistance of the pellets decreases with an increase in relative humidity, with the maximum sensitivity at 4-weight-percent loading.

These researchers from the Université Paul Sabatier in France and Vishay Resistors in Belgium prepared and characterized-they report for the first time-single-phase spinel manganese cobalt oxide (Mn3-xCoxO4) dense ceramics. They compared the Mn3-xCoxO4 with currently commercially available Mn3-xNixO4 and Mn3-xCuxO4 and report that the high energetic constants and low resistivities of the new ceramics present promising interest for industrial applications.

This team of researchers from China’s Northwestern Polytechnical University and Lanzhou Institute of Physics studied T300 carbon fiber and a SiC-coated C/SiC composite made from T300 carbon fiber under an atomic-oxygen environment. The team reports that the carbon fiber experienced significant degradation but that the SiC-coating on the C/SiC composite experienced a much lower erosion rate and that the C/SiC composites had no significant change in flexural properties after one-year of exposure to atomic-oxygen atmosphere.

Researchers from the National Cheng Kung University and the National United University in Taiwan used Bi2O3-B2O3-ZnO-SiO2 glass as a sintering aid in the preparation of Bi-Zn-codoped Co2Y low-temperature-fired ferrites. They report that this process provides promising candidates for multilayer chip magnetic devices for microwave applications.

This team of researchers from Egypt and Libya reports that it has improved the physicomechanical and refractory properties of two commercially available refractory castables based on mullite or magnesia aggregates through addition of nano-magnesium aluminate spinel powder.